Secondary display system for computer

ABSTRACT

Apparatus and method for a secondary display system for a computer are disclosed. A secondary display system of the present invention includes a flat panel display configured such that the display is conveniently located both during and between use thereof. The system comprises a liquid crystal display module (LCDM), a corresponding display controller connected to the LCDM via an appropriate interface, and a mounting device connected to the LCDM for mounting and positioning the LCDM in close proximity to the monitor of a computer. In a preferred embodiment, the mounting device comprises a rectangular plate, which is horizontally disposed between a chassis and a monitor of the computer, and the positioning means comprises a single axis hinge, which is connected to a front corner of the plate such that the hinge rotates on a vertical axis. In one embodiment, one edge of the LCDM is attached to the hinge so that the LCDM may be rotated on a vertical axis. In another embodiment, the LCDM is pivotally attached to two arms, which in turn are pivotally attached to the hinge so that the LCDM can be rotated about multiple vertical axis. During use, the LCDM may be rotated such that its display screen is coplanar with the display screen of the monitor. Between uses, the LCDM may be rotated such that its display screen is substantially orthogonal to the display screen of the monitor.

This is a divisional of application No. 08/544,341 filed Oct. 17, 1995,now U.S. Pat. No. 5,594,620 issued Jan. 14, 1997, which is acontinuation of Ser. No. 08/092,846 filed on Jul. 16, 1993 now U.S. Pat.No. 5,590,021.

TECHNICAL FIELD

The invention relates generally to display systems for computers and,more specifically, to a secondary display system for a computer.

BACKGROUND OF THE INVENTION

Modem personal computers (PCs) make extensive use of graphical userinterfaces (GUIs). GUIs enable multiple data sets and applications to besimultaneously displayed and manipulated by means of "windows" imaged onthe PC's display and a pointing device for controlling the size andplacement of the windows. Windows may be partially or completelyoverlapping, reduced to iconic representation, or expanded to fill theentire display. A pervasive example of the above-described type of GUIis the Microsoft Windows software program.

A problem commonly experienced by GUI users results during attempts todisplay more than one large window on a single computer display at onetime, as a typical display is too small to display two or more windowswithout substantial overlap therebetween. A solution to this problem hasbeen to develop monitors that are larger and have a substantiallygreater display area than typical monitors. Such monitors are capable ofdisplaying several large windows simultaneously; however, they generallyrequire more desk space than most users are willing or able to spare.

Dual monitor systems are also known and employed to enable the displayof more than one large window at a time. In such dual monitor systems, asecondary display controller and associated display are interfaced tothe computer in parallel with the primary display controller andassociated display. GUI software is commercially available which regardsthe dual displays as a single correspondingly larger virtual displaysystem, so that cursor manipulations and data entry move from screen toscreen in a natural manner. A single data window may be configured tospan both screens, although the physical gap in the middle of the largervirtual display, due to the fact that computer monitors cannot bepositioned sufficiently close together, is distracting to most users.More typically, one display will be used for displaying active dataentry, while the other will be used for displaying static referencedata, for example, help screens. Dual display systems suffer the samedrawback as large display systems with respect to the amount of spacerequired to use them.

Because the allocation of additional desk space by a user to his or hercomputer is usually unacceptable or impossible, despite the prospect ofimproved productivity that may be achieved therewith, computersincorporating larger monitors or dual display systems are not inwidespread use. Therefore, what is needed is an apparatus for providinga computer with a larger display area that does not require additionaldesk space and that minimizes the physical gap inherent in a dualdisplay system.

SUMMARY OF THE INVENTION

The foregoing problems are solved and a technical advance is achieved byan apparatus for a secondary display system for a computer. In adeparture from the art, a secondary display system of the presentinvention includes a flat panel display configured such that the displaymay be conveniently located both during and between use thereof. Thesystem comprises a liquid crystal display module (LCDM), a correspondingdisplay controller for interfacing the LCDM to the computer, and meansconnected to the LCDM for mounting and positioning the LCDM in closeproximity to the primary display of the computer.

The LCDM comprises an addressably matrixed display surface and backlightsystem enclosed in a relatively slim housing. The corresponding displaycontroller comprises a printed circuit board which includes all thecontrol, storage and interface circuitry necessary for interfacing theLCDM to a PC. The controller may be embodied as an integrated circuit(IC) card that is plugged in to an expansion bus resident on thecomputer, or may be built into the motherboard of the PC. The controllerinterfaces with the LCDM via a cable.

Although the mounting and positioning means may take any number ofdifferent physical forms, its function is to enable the LCDM to bepositioned conveniently close to the primary display of the computer, soas to minimize the physical gap between the displays, and to beretracted to lie flat against the primary display when not in use.

In a preferred embodiment, the mounting means comprises a rectangularplate, which may be constructed of metal or hard plastic, for example.The positioning means comprises a single axis hinge, which is connectedto a front comer of the plate such that the axis of the hinge isorthogonal to the plane of the plate. One edge of the LCDM is attachedto the hinge so that the LCDM may be rotated on a vertical axis in amanner similar to a household door. The plate is interposed between thecomputer's chassis and monitor, so that the monitor rests atop the plateto provide a counterbalancing moment to the cantilevered LCDM. Anycabling necessary for interfacing the LCDM with the display controlleris routed through the hinge, in a manner similar to a notebook computer.

During use, the LCDM may be rotated and positioned such that its displaysurface is substantially coplanar with the display surface of themonitor. Between uses, the LCDM may be rotated toward the back of themonitor and positioned so that its display surface is substantiallyorthogonal to the monitor, thereby minimizing the amount of spaceoccupied by the LCDM.

In an alternative embodiment, the mounting means comprises a pluralityof clamping devices, rather than a horizontal plate, which clampingdevices are connected to the hinge along the axis thereof. Similar tothe preferred embodiment, one edge of the LCDM is attached to the hingesuch that the LCDM is rotatable on the axis of the hinge. Use of theclamping devices, rather than the plate, enables the secondary displaysystem to be used in connection with portable, as well as desktop,computers and further enables alternate placement of the LCDM relativeto the computer display. For example, the LCDM may be attached to thetop, rather than a side, of the display and rotated back to rest atopthe display when not in use.

In another alternative embodiment, the LCDM comprises a two sideddisplay and the positioning means further comprises first and secondarms connected at opposite ends of the hinge and extending in the samedirection perpendicular to the hinge. The free end of the first arm ispivotally connected to the center of one edge of the LCDM. The free endof the second arm is pivotally connected to the center of the oppositeedge of the LCDM. As a result, the LCDM may be rotated on an axisextending through the center of the LCDM as defined by the pivotalconnections. In addition, the LCDM may be rotated on the axis of thehinge. In this alternative embodiment, the mounting device may compriseeither a horizontal plate or a plurality of clamping devices, asdescribed above.

A technical advantage achieved with the invention is that the secondarydisplay may be positioned in close proximity to the computer display sothat any physical gap that results when the two displays are used as asingle large display is minimized.

A further technical advantage achieved with the invention is that thesecondary display requires less desk space than prior art dual displaysystems.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a preferred implementation of asecondary display system embodying features of the present invention.

FIG. 2 is an exploded view of the implementation of the secondarydisplay system of FIG. 1.

FIG. 3 is an alternative embodiment of the secondary display system ofthe present invention.

FIG. 4 is another alternative embodiment of the secondary display systemof the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIGS. 1 and 2 illustrate a preferred embodiment of a secondary displaysystem of the present invention. Referring to FIG. 2, the referencenumeral 10 designates the secondary display system. The display system10 is implemented on a computer 12 having a chassis 14 connected to adisplay or monitor 16, which rests on the top surface of the chassis 14,via a cable 17. The system 10 comprises a mounting arrangement, such asa plate 18, a positioning element, such as a single axis hinge 20, aliquid crystal display module (LCDM) 22, and a display controller 24. Inthe illustrated embodiment, the plate 18 is a horizontally disposedrectangular member constructed of metal or hard plastic, for example.The hinge 20 is connected to a comer of the plate 18 such that an axis25 of the hinge 20 is orthogonal to the plane of the plate 18. One edgeof the LCDM 22 is connected to the hinge 20 such that the LCDM 22 isrotatable on the axis 25 of the hinge 20, in a manner similar to ahousehold door. The display controller 24 comprises the circuitrynecessary for controlling the operation of the LCDM 22 and may embodiedin an IC card inserted into an expansion bus (not shown) resident on thecomputer 12 or built in to the motherboard of the computer 12.Controllers such as the controller 24 are well known to those skilled inthe art and will not be further described.

The controller 24 is connected to the LCDM 22 via an interface cable 26.The cable 26 and other cabling or circuitry necessary for interfacingthe LCDM 22 with the controller 24 are routed through the hinge 20,similar to the method used in connection with notebook and otherportable computers. The plate 18 is placed on top of the chassis 14 andthe monitor 16 is positioned so that it rests on the plate 18, therebyproviding a counterbalancing moment to the cantilevered LCDM 22.

During use of the system 10, the LCDM 22 may be rotated and positionedsuch that its display surface 28 is substantially coplanar with thedisplay surface 29 of the monitor 16. Between uses, the LCDM 22 may berotated toward the back of the monitor and positioned so that itsdisplay surface 28 is substantially orthogonal to that of the monitor16, thereby minimizing the amount of desk space occupied by the LCDM 22.

Referring to FIG. 3, a reference numeral 30 designates an alternativeembodiment of the secondary display system 10 (FIGS. 1 and 2). Similarto the system 10, the system 30 includes the LCDM 22 connected to thedisplay controller 24 (FIGS. 1 and 2) via the interface cable 26 (FIGS.1 and 2), and a positioning element comprising the single axis hinge 20,which is attached to one edge of the LCDM 22. Unlike the system 10,however, the mounting arrangement of the system 30 comprises a pluralityof clamping devices 32a, 32b for clamping the system 20 to the displayof a computer (not shown) rather than the plate 18. Therefore, thesystem 30 may be used in combination with both conventional desktop andportable computers. Further, the system 30 may be attached to enable avariety of display configurations, e.g., side-by-side displays or upperand lower displays.

Referring to FIG. 4, a reference numeral 40 designates anotheralternative embodiment of the secondary display system 10 (FIGS. 1 and2). Similar to the system 10, the mounting arrangement of the system 40comprises the plate 18. However, the positioning element of the system40 comprises the hinge 25 and first and second coplanar arms 42a, 42bconnected to the hinge 25 at opposite ends thereof and in a mannerperpendicular to the axis 25 of the hinge 20. The first arm 42a ispivotally connected to the center of an edge 44a of a two-sided LCDM 46and the second arm 42b is pivotally connected to the center of theopposite edge 44b of the LCDM 46. Therefore, in addition to beingrotatable on the axis 25 of the hinge 20, the LCDM 46 is also rotatableon a second axis 8, which is parallel to the axis 25, to enable a userto rotate the LCDM 46 to use either or both sides of the LCDM 46, aswell as to rotate it out and back during use and between uses.

Therefore, with respect to any of the illustrated embodiments, asecondary display is provided on a computer which display utilizes aminimum amount of desk space and which is conveniently positioned inclose proximity to the primary display of the computer.

It is understood that the present invention can take many forms andembodiments. The embodiments shown herein are intended to illustraterather than to limit the invention, it being appreciated that variationsmay be made without departing from the spirit or the scope of theinvention. For example, mounting arrangement of the system 40 maycomprise clamping devices 32a, 32b rather than the plate 18. Further,the system 10, 20 or 40 may be permanently, rather than removably,mounted to a computer.

Although illustrative embodiments of the invention have been shown anddescribed, a wide range of modification, change and substitution isintended in the foregoing disclosure and in some instances some featuresof the present invention may be employed without a corresponding use ofthe other features. Accordingly, it is appropriate that the appendedclaims be construed broadly and in a manner consistent with the scope ofthe invention.

What is claimed is:
 1. A secondary display system for a computer havinga primary display, the system comprising:a flat panel display operatingas a secondary display to said primary display of said computer; adisplay controller electrically connected to said flat panel display forinterfacing said flat panel display to said computer; means connected tosaid flat panel display for positioning said flat panel display relativeto said computer and to said primary display, said positioning meansdefining an axis on which said flat panel display is rotatable; andmeans connected to said positioning means for supporting said systemrelative to said computer such that said positioning means is adjacentand parallel to an edge of said primary display.
 2. The system of claim1 wherein said positioning means comprises a hinge.
 3. The system ofclaim 2 wherein said positioning means further comprises:a first armconnected to said hinge near a first end of said first arm and pivotallyconnected to a first edge of said flat panel display near a second endof said first arm; and a second arm connected to said hinge near a firstend of said second arm and pivotally connected to a second edge of saidflat panel display directly opposite said first edge near a second endof said second arm; wherein said first and second arms are coplanar andsaid flat panel display is rotatable on a second axis defined by saidpivotal connections.
 4. The system of claim 3 wherein said computercomprises a computer chassis and a monitor resting on a top surfacethereof and said mounting means comprises a substantially planar plateinterposed between said chassis and said monitor to provide acounterbalancing moment to said flat panel display.
 5. The system ofclaim 4 wherein said flat panel display comprises a two-sided display.6. The system of claim 1 wherein said flat panel display comprises aliquid crystal display module.
 7. A secondary display system for acomputer having a primary display, the system comprising:a flat paneldisplay operating as a secondary display to said primary display of saidcomputer; a display controller electrically connected to said flat paneldisplay for interfacing said flat panel display to said computer; ahinge parallel to an edge of said flat panel display and connected tosaid edge of said flat panel display for enabling rotation of said flatpanel display about an axis of said hinge between first and secondpositions relative to said primary display of said computer; and meansconnected to said hinge for mounting said system on said computer suchthat said hinge is adjacent and parallel to an edge of said primarydisplay.
 8. The system of claim 7 wherein said first position of saidflat panel display is defined as a display surface of said flat paneldisplay being substantially coplanar with a display surface of saidprimary display and said second position of said flat panel display isdefined as said display surface of said flat panel display beingsubstantially orthogonal to said display surface of said primarydisplay.
 9. The system of claim 7 wherein said flat panel displaycomprises a liquid crystal display module.
 10. A secondary displaysystem for a computer, the system comprising:a flat panel display; adisplay controller electrically connected to said flat panel display forproviding an electrical interface between said flat panel display andsaid computer;, means connected to said flat panel display forpositioning said flat panel display relative to said computer, saidpositioning means comprising:a hinge defining a first axis of rotationof said flat panel display; a first arm extending perpendicularly fromsaid hinge, a first end of which first arm is connected to said hingeand a second end of which first arm is pivotally connected to a firstedge of said flat panel display; and a second arm extendingperpendicularly from said hinge, a first end of which second arm isconnected to said hinge and a second end of which second arm ispivotally connected to a second edge of said flat panel display directlyopposite said first edge; wherein said first and second arms arecoplanar and said pivotal connections define a second axis of rotationof said flat panel display; and means connected to said positioningmeans for mounting said system to said computer.
 11. The system of claim10 wherein said computer comprises a computer chassis and a displaymonitor disposed on a top surface thereof, and said mounting meanscomprises a horizontal plate interposed between said chassis and saidmonitor to provide a counterbalancing moment to said flat panel display.12. The system of claim 10 wherein said flat panel display comprises aliquid crystal display module.
 13. The system of claim 12 wherein saidcomputer is a portable computer.
 14. The system of claim 10 wherein saidflat panel display comprises a two-sided liquid crystal display module.15. A computer incorporating a secondary display system, the computercomprising:a main chassis; a primary display interfaced to said mainchassis via a primary display controller;, a secondary displaycomprising a flat panel display interfaced to said main chassis via asecondary display controller, said secondary display being pivotallyconnected to said primary display for enabling rotation of saidsecondary display between first and second positions relative to saidprimary display.
 16. The computer of claim 15 wherein said firstposition of said secondary display is defined as a display surface ofsaid secondary display being substantially parallel to a display surfaceof said primary display and said second position of said secondarydisplay is defined as said display surface of said secondary displaybeing substantially orthogonal to said display surface of said primarydisplay.
 17. The computer of claim 15 wherein said primary display is aCRT.
 18. The computer of claim 15 wherein said primary display is a flatpanel display.
 19. The computer of claim 15 wherein said secondarydisplay is a liquid crystal display module.
 20. A display system for acomputer, the system comprising:a primary display interfaceable to amain chassis of a computer; a secondary display interfaceable to saidmain chassis and movably connected to said primary display for enablingmovement between first and second positions relative to said primarydisplay.
 21. The system of claim 20 wherein in said first position, saidsecondary display is adjacent said first display and is disposed topermit convenient simultaneous viewing of said primary display and saidsecondary display by a user, andin said secondary position, a top edgeof said secondary display extends along a side of said primary displayfor compactness.
 22. The system of claim 20 wherein said secondarydisplay is rotatably connected to said primary display.
 23. The systemof claim 22 wherein said primary display comprises a CRT and saidsecondary display comprises a flat panel display.
 24. The system ofclaim 23 wherein said secondary display comprises a liquid crystaldisplay module.